1. Field of the Invention
The present invention concerns a method and machine for manufacturing a multiplicity of linked pockets for making up expanding files comprising a plurality of partitions joined along three edges to constitute respective filing pockets by a flexible material concertina-folded to constitute respective gussets.
2. Description of the Prior Art
Files comprising a plurality of parallel partitions joined along the edges to constitute respective filing pockets by a flexible material concertina-folded to constitute respective gussets are known in the art.
Such files are usually manufactured one at a time using manual methods, involving various operations to form the concertina folds and to prepare and place the partitions in the folds, and various finishing operations.
This type of manufacturing method is highly labor intensive and calls for skilled labor. The resulting expanding files are expensive. The rate of manufacture is also low, and is often insufficient to meet demand.
The present invention is intended to overcome the aforementioned disadvantage by proposing a method of manufacturing a multiplicity of linked pockets for making up expanding files and a machine for implementing that method, whereby high rates of manufacture are obtained with less labor and the product is of excellent finish.
The invention consists in a method for manufacturing a multiplicity of linked pockets for making up expanding files comprising a plurality of parallel partitions joined along three edges to constitute respective filing pockets by a flexible material concertina-folded to constitute respective gussets, characterised in that a flat strip of the flexible material is progressively folded longitudinally to form a substantially U-shaped channel, a length of the material equivalent to the developed width of a gusset is drawn forward, a precut partition with folded and glued tabs on at least two sides is placed at the rear of the drawn forward section of material, perpendicular to the longitudinal axis thereof, a fold is formed centrally of said drawn forward section of material by pushing the three edges of the channel inwardly, the fold thus formed is compressed in the longitudinal direction to bond said partition, and a new length of material is drawn forward, this sequence of operations being repeated to form a multiplicity of pockets.
The invention further consists in a machine for manufacturing a multiplicity of linked pockets for making up expanding files comprising a plurality of parallel partitions joined along three edges to constitute respective filing pockets by a flexible material concertina-folded to constitute respective gussets, characterised in that it comprises, from the rear towards the front: a spool of the flexible material, a member shaped to progressively fold the material into a substantially U-shaped channel, means for drawing forward a length of the material equivalent to the developed width of a gusset, means disposed around the three sides of the U-shaped channel to form respective gussets by exerting a pushing action by virtue of a movement substantially perpendicular to the longitudinal axis of the material, means for compressing the gussets thus formed, retractable means for restraining the multiplicity of pockets previously formed during the formation of each gusset, and means for braking the forward motion of the multiplicity of pockets.
According to another feature of the invention, partition feed means are disposed above the position of the drawn forward section of material, comprising a plate movable between a substantially horizontal position in which it receives a partition with folded and glued tabs and a substantially vertical position in which it is positioned, with the partition, at the rear of the drawn forward section of material. The surface of the plate receiving the partition is connected to suction means for retaining the partition during its transfer.
According to another feature of the invention, at the front of the machine are means for restraining and sectioning the multiplicity of linked pockets, comprising a frame movable vertically and adapted to engage in a gusset to permit the multiplicity of linked pockets to be sectioned by means of a cutting tool.
A machine in accordance with the invention has undeniable advantages as compared with the prior art. It provides for the continuous automatic manufacture with little human intervention of linked pockets for making up expanding files comprising a plurality of parallel partitions joined to constitute respective filing pockets.
The prior art problem of productivity is overcome by the automatic operation of the machine, resulting in high manufacturing rates. The cost of manufacturing files from linked pockets produced by the method in accordance with the invention is substantially lower than is the case for prior art files of the same type, due in part to the increased production rate and in part to the reduced labor requirement. Another significant advantage is that the folds of the gussets are formed mechanically, and are therefore perfectly regular to confer an excellent finish.
Further objects and advantages will appear from the following description of an example of the invention, when considered in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.